1. Field of the Invention
The present invention relates generally to the field of tarp covers for trucks, and more specifically, to a rear arm assembly for a tarp cover system that can be used with a three-piece tailgate on a farm truck, dump truck, or similar vehicle.
2. Description of the Related Art
The present invention is a rear arm assembly for a side-to-side tarp cover system for a farm truck, dump truck or similar vehicle with a three-piece tailgate of the type shown in FIG. 1. There exist a number of side-to-side tarp cover systems for trucks, some of which are manually operated and others of which are electronically operated. Among the electronically operated tarp cover systems are those depicted in U.S. Pat. Nos. 6,199,935, 6,206,449 and 6,513,856, discussed below. An example of a manually operated side-to-side tarp system is described in U.S. Pat. No. 7,513,561, also discussed below. Unlike the present invention, none of these systems is specifically designed to work with a three-piece tailgate.
U.S. Pat. No. 6,199,935 (Waltz et al., 2001) discloses a flexible sheet cover apparatus for a load-carrying box on a land vehicle in which an arm is coupled to a roller for rolling and unrolling the flexible sheet from side to side. The arm is in the form of a box beam with a fixed length, and the arm has a slot. A pin is coupled to the load-carrying box and slidably engaged in the slot in the arm to define a pivot for the arm. The roller remains in constant contact with the top edges of the two non-contiguous walls that form the load-carrying box. A motor is fixed to the arm between the roller and the slot, and a drive unit enclosed within the box beam couples the motor to the roller.
U.S. Pat. No. 6,206,449 (Searfoss, 2001) provides an apparatus for extending and retracting a cover over a bed of a truck. The main arm, which is located at the rear of the truck bed, has a first base and a first extension. The bearing arm, which is located at the front of the truck bed, has a second base and a second extension. The first extension is pivotally connected to the upper end of the first base, and the second extension is pivotally connected to the upper end of the second base. A reel extends between distal ends of the first and second extensions. A motor is mounted on the distal end of either the first or second extension and is also connected to the distal end of the reel. U.S. Pat. No. 6,527,331 (Searfoss, 2003) utilizes a similar arm assembly.
In three other Searfoss patent filings, the inventor depicts an arm assembly for a flexible tarp cover of a truck trailer in which the arm assembly comprises a base plate that is centrally situated on the rear end of the trailer and three extension members that protrude from the base plate. Each extension member terminates in a torsion spring that in turn engages with another extension member, each of which terminates in a rotatable wheel. This invention is described in U.S. Pat. No. 7,246,838 (Searfoss, 2007), U.S. Pat. No. 7,726,720 (Searfoss, 2010), and U.S. Patent Application Pub. No. 20050057068 (Searfoss, 2005).
U.S. Pat. No. 6,513,856 (Swanson et al., 2003) involves a mechanism for rolling and unrolling a tarp over a trailer container. An electrically operated drive assembly is used to roll the roll bar back and forth between longitudinal edges of the container. The drive assembly comprises an electric motor and a gear reduction mechanism, both of which are supported on a telescoping tube assembly that is pivotably attached to the front of the container. A double reel member is fixedly attached to the forward end of the roll bar, and a single reel member is fixedly attached to the rearward end of the roll bar. Constant force spring members are fixedly attached to the double and single reel members and also to hinge plates mounted on the side of the container.
U.S. Pat. No. 7,513,561 (Royer, 2009) discloses a device for covering and uncovering the top of a container with a tarp, the device comprising a rod, a rod rotating component, and an actuator. The tarp is rolled around the rod when the cover is in a retracted position, and the rod rotating component is couple to the rod such that rotating the rod rotating component around its longitudinal axis also rotates the rod around its longitudinal axis. The rod rotating component is linked to an actuator that is operated manually and that causes the rod rotating component to rotate about its longitudinal axis. The length of the rod rotating component varies to allow the rod to remain linked to the actuator as the rod travels over the top of the container.
U.S. Pat. No. 7,188,887 (Schmeichel, 2007) describes a roll tarp system with a front bracket, front inner arm, front outer arm, rear bracket, rear inner arm, and rear outer arm. A flexible front bias member allows the front inner arm to pivot laterally with respect to the front outer arm and applies a force to retain the front inner arm and front outer arm in a concentrically aligned position. U.S. Pat. No. 7,195,304 (Schmeichel, 2007) includes a second bias member attached to the rear outer arm and rotatably connected to the rear end of the roller attached to the tarp.
Examples of tarp covering systems that involve front-to-back rather than side-to-side retraction and extension systems include: U.S. Pat. 7,111,891 (O'Brian et al., 2006); U.S. Pat. No. 6,893,071 (Chabot, 2005); U.S. Pat. No. 6,318,790 (Henning, 2001); U.S. Pat. No. 6,942,274 (Henning, 2005); and U.S. Pat. No. 6,575,519 (Henning, 2003). None of the above prior art references (involving side-to-side or front-to-back systems) provides a rear arm for a tarp cover system that is specifically designed to work with a three-piece tailgate.